gstreamer/gst/law/mulaw-encode.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <gst/gst.h>
#include "mulaw-encode.h"
#include "mulaw-conversion.h"

extern GstPadTemplate *mulawenc_src_template, *mulawenc_sink_template;


/* Stereo signals and args */
enum {
  /* FILL ME */
  LAST_SIGNAL
};

enum {
  ARG_0
};

static void		gst_mulawenc_class_init		(GstMuLawEncClass *klass);
static void		gst_mulawenc_init			(GstMuLawEnc *mulawenc);

static void		gst_mulawenc_set_property			(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
static void		gst_mulawenc_get_property			(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);

static void		gst_mulawenc_chain			(GstPad *pad, GstBuffer *buf);


static GstElementClass *parent_class = NULL;
/*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */

static GstPadLinkReturn
mulawenc_link (GstPad *pad, GstCaps *caps)
{
  GstCaps* tempcaps;
  gint rate, channels;
  
  GstMuLawEnc* mulawenc = GST_MULAWENC (GST_OBJECT_PARENT (pad));
  
  if (!GST_CAPS_IS_FIXED (caps))
    return GST_PAD_LINK_DELAYED;  
  
  if (!gst_caps_get (caps, "rate", &rate,
                           "channels", &channels,
                           NULL))
    return GST_PAD_LINK_DELAYED;
  
  tempcaps = GST_CAPS_NEW (
	      "sinesrc_src_caps",
	      "audio/x-mulaw",
          "depth",    GST_PROPS_INT (8),
          "width",    GST_PROPS_INT (8),
          "signed",   GST_PROPS_BOOLEAN (FALSE),
          "rate",     GST_PROPS_INT (rate),
          "channels", GST_PROPS_INT (channels),
        NULL);
  
  return gst_pad_try_set_caps (mulawenc->srcpad, tempcaps);
}		

GType
gst_mulawenc_get_type(void) {
  static GType mulawenc_type = 0;

  if (!mulawenc_type) {
    static const GTypeInfo mulawenc_info = {
      sizeof(GstMuLawEncClass),      NULL,
      NULL,
      (GClassInitFunc)gst_mulawenc_class_init,
      NULL,
      NULL,
      sizeof(GstMuLawEnc),
      0,
      (GInstanceInitFunc)gst_mulawenc_init,
    };
    mulawenc_type = g_type_register_static(GST_TYPE_ELEMENT, "GstMuLawEnc", &mulawenc_info, 0);
  }
  return mulawenc_type;
}

static void
gst_mulawenc_class_init (GstMuLawEncClass *klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass*)klass;
  gstelement_class = (GstElementClass*)klass;

  parent_class = g_type_class_ref(GST_TYPE_ELEMENT);

  gobject_class->set_property = gst_mulawenc_set_property;
  gobject_class->get_property = gst_mulawenc_get_property;
}

static void
gst_mulawenc_init (GstMuLawEnc *mulawenc)
{
  mulawenc->sinkpad = gst_pad_new_from_template(mulawenc_sink_template,"sink");
  mulawenc->srcpad = gst_pad_new_from_template(mulawenc_src_template,"src");
  gst_pad_set_link_function (mulawenc->sinkpad, mulawenc_link);

  gst_element_add_pad(GST_ELEMENT(mulawenc),mulawenc->sinkpad);
  gst_pad_set_chain_function(mulawenc->sinkpad,gst_mulawenc_chain);
  gst_element_add_pad(GST_ELEMENT(mulawenc),mulawenc->srcpad);
}

static void
gst_mulawenc_chain (GstPad *pad,GstBuffer *buf)
{
  GstMuLawEnc *mulawenc;
  gint16 *linear_data;
  guint8 *mulaw_data;
  GstBuffer* outbuf;

  g_return_if_fail(pad != NULL);
  g_return_if_fail(GST_IS_PAD(pad));
  g_return_if_fail(buf != NULL);

  mulawenc = GST_MULAWENC(GST_OBJECT_PARENT (pad));
  g_return_if_fail(mulawenc != NULL);
  g_return_if_fail(GST_IS_MULAWENC(mulawenc));

  linear_data = (gint16 *)GST_BUFFER_DATA(buf);
  outbuf=gst_buffer_new();
  GST_BUFFER_DATA(outbuf) = (gchar*)g_new(gint16,GST_BUFFER_SIZE(buf)/4);
  GST_BUFFER_SIZE(outbuf) = GST_BUFFER_SIZE(buf)/2;

  mulaw_data = (gint8*)GST_BUFFER_DATA(outbuf);
  mulaw_encode(linear_data,mulaw_data,GST_BUFFER_SIZE(outbuf));

  gst_buffer_unref(buf);
  gst_pad_push(mulawenc->srcpad,outbuf);
}

static void
gst_mulawenc_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
  GstMuLawEnc *mulawenc;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail(GST_IS_MULAWENC(object));
  mulawenc = GST_MULAWENC(object);

  switch (prop_id) {
    default:
      break;
  }
}

static void
gst_mulawenc_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
  GstMuLawEnc *mulawenc;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail(GST_IS_MULAWENC(object));
  mulawenc = GST_MULAWENC(object);

  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}